I cannot vouch for how the FMA copilot device works, but it does work very well. The main controversy over the device is if it is an assist or a detterent to learning to fly a fixed wing RC airplane. Although there are many stories of people picking up a controller and flying I have never seen it happen. Most students cans save hundreds of dollar with an instructor. It is harder than it looks. I suspect that the quick learning claims apply to powered gliders that are inherently stable by design. The FMA copilot approaches that degree of stability. John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 johnferrell@earthlink.net Dixie Competition Products NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" ----- Original Message ----- From: "Peter L. Peres" To: Sent: Saturday, July 26, 2003 4:26 AM Subject: Re: [OT]: Dynamic tilt angle sensor > > The ones like the FMA Co-Pilot are even simpler. For each axis there > > are two sensors pointed in opposite directions. It just looks to see > > which is picking up more light; if they are the same it's level. > > But the sky is not evenly lit except at noon on the equator, and the > horizon does not delimit a luminance border, more a color border, and even > that is not so clear. And this assumes free space, no buildings, trees, > etc, and no clouds (esp. no partial cover). > > I wrote about this before. You can index a XYZ accelerator inertial ins by > looking for the times when the total sum vector of the three axes equals g > to 0.5% (eight bits are enough!). This gives vertical to better than half > a degree. The best way to make sure that this happens often is to put the > ins on active (or not) gimbals inside the vehicle so it tries to point > down and succeeds most of the time. Then you have a stabilised platform > and it should be easier to calculate what you need. Note that I did not do > this, but I am under the 'influence' of some control theory books I have > read recently. > > Peter > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads